1. Field of the Invention
The present invention relates to an image forming apparatus, an image printing method, and a computer-readable recording medium having stored therein an image printing control program for printing images on continuous paper at fixed intervals.
2. Description of the Related Art
In an image forming apparatus that prints images on continuous paper, it is desirable to set an interval between the images, that is, a blank region as small as possible because the interval becomes a break. However, high resolution of printing jobs has been further enhanced. The image interval set small is late for printing timing for forming the next image.
As measures against this problem, Japanese Patent Application Laid-Open No. 2008-15609 (Cited Reference 1) proposes a continuous-paper printing apparatus that determines whether generation of image data is in time for printing timing based on the image data and, when determining that the generation of the image data is late, dynamically inserts a predetermined number of skip pages among printing pages based on the generated image data to continue a printing operation without stopping the printing operation halfway in printing.
However, in the technique proposed in Cited Reference 1, it is possible to prevent the printing operation from being stopped halfway in the printing. However, since blank pages are inserted, regions to be breaks increase. It is conceivable to change the size of the image interval according to necessity. However, when processing is performed in a post-processing apparatus after the printing ends, in some case, die cutting, cutting, labeling, or the like is performed without performing precise alignment assuming that a printed image interval is fixed. If intervals among images are irregular, proper post-processing cannot be performed.
In the case of an analog printing machine, since the analog printing machine is configured to repeatedly print an image, a plate of which is manufactured, at a fixed cycle. Therefore, if image forming speed is fixed, it is easy to guarantee that images are formed at equal intervals. On the other hand, in the case of a digital printing machine, an image is written after image data is prepared in a unit of a page. Time required for the preparation fluctuates according to complexity of RIP (raster image processor) processing of the image data, presence or absence of page numbering, and the like. Therefore, even if an image size is always fixed, it is difficult to guarantee image arrangement at equal intervals on continuous paper. The image preparation time also depends on a processing ability of an image forming apparatus. Therefore, the image preparation time cannot be accurately calculated unless printing data is actually converted into image data from which an image can be formed. The demand of the image interval for the printing on the continuous paper cannot be satisfied.
If a delay of 1 millisecond occurs at linear velocity of 300 mm/second, the image interval delays by 1*300/1000=0.3 mm. This is unallowable variation in the field of commercial printing.
At least one object of the present invention is to provide an image forming apparatus, an image printing method, and a computer-readable recording medium having stored therein an image printing control program that can set an unnecessary blank region as small as possible such that image preparation processing is in time for image formation and can surely perform post-processing by arranging images at equal intervals and printing the images.